1. Field of the Invention
The present invention relates to a technique for the assignment and use of node addresses in a small, wireless data communications network or a small, wireless sub-network of a larger network and, more particularly, to a technique which permits network configuration data to be sent with every message without the need for complex routing protocols and without adding significant overhead to the network communications.
2. Description of the Prior Art
Conventional wireless networks typically permit nodes to communicate only if they are within range of each other (i.e., in the same "cell"). Sophisticated software protocols are typically required to control message traffic to permit communication from one cell to another. Such protocols typically add substantial overhead to the network communications. Also, to provide sufficient communications range, such systems typically require each node to have relatively powerful transmitters to communicate with all nodes in that cell. However, even when relatively powerful transmitters are used, communications may be interrupted when the source node or a destination node leaves the cell. Moreover, such systems are limited by the distance and direction to the destination node from the source node, and, as a result, complicated routing information must be transmitted periodically to all nodes in the network.
There has been a lot of work in the field of routing protocols in wireless networks. Conventional systems address the problem of routing protocols in small to large networks in which the nodes are not known beforehand by identifying the nodes identified only by their "IP addresses". The associated routing protocols attempt to obtain a route from source to destination for packet communication. Such wireless networks can be classified under two broad categories: cellular network and ad hoc network.
In a cellular network there arc few special nodes (commonly referred to as base stations) spread over an area. These "special nodes" can communicate amongst themselves via wired network, satellite, higher transmit power, etc. The users which normally have lower transmit power communicate with one of these special nodes. If there is a need to communicate with other wireless nodes, then message data is exchanged via other special nodes. However, there are several protocols to keep track of, such as, where the nodes are and what happens when moving nodes move from one cell to another.
In an ad hoc network on the other hand, there are no known special nodes. The network among the nodes has to first establish itself. Nodes exchange "Hello" messages to find neighbors and other information about neighbors. Some protocols require frequent exchanges of their own positions, links, etc. and, based on that information, all nodes attempt to keep optimized updated routes to all nodes in the network. Other sets of protocols do not keep updated route information, but when a source node needs to communicate with a specific destination, the destination node will be searched for.
It is desired to provide a communications system with simple software protocols for controlling message traffic which are concise enough to be appended to each message without adding significant overhead to the communications system. Such protocols should also allow ad hoc communications among the nodes in an ad hoc wireless network without regard to the proximity of the other members of the network, particularly the destination node. The present invention has been designed to meet these needs in the art.